* Update search.py

Commenting issues fixed (spacing and punctuation was off sometimes).

* Update agents.py

* Update canvas.py

Grammar

* Update grid.py

* Update learning.py

Added period

* Update logic.py

Fix quoting

* Update mdp.py

Fixed quoting

* Update nlp.py

Capitalization and punctuation fixes

* Update planning.py

* Update probability.py

* Update rl.py

'th' to 'the'

* Update search.py

* Update text.py

* Update utils.py

* Update utils.py

* Update utils.py

* Update learning.py

Typo

* Update utils.py

Style: delete excess parentheses. In some of these cases you need to read ahead to see that the paren is not introducing a tuple, for example.

* Replaced mean with standard lib function introduced in 3.4

* #TODO Replaced every with all

* Proper names for variables introduced in 2to3 conversion.

Following a suggestion by C.G.Vedant, changed |implies| to |’==>’|

* removes obsolete Fig dictionary from utils.py

* modified rl notebook according to the new Figure conventions

* removes 'import Fig' and changed the names of Figures

* fixes a small error (by me) in executing the cells in rl notebook

*  Used isclose from utils to maintain compatibilty for 3.4

* Removed redundant distancesquared function

* Removed duplicate definition of clip in grid.py and used import from instead.

* Fixed spelling typo

Add InfixOps, refactor expo and Expr

* changes a typo of file name to /aima-data

* modified some documentaion and removed doc tests

* changed the names like Fig[2, 3] and added unit tests for search.py

Remove count_if, find_if, every, some, Struct; replace them with modern
Python equivalents.